This invention relates generally to at least partial removal of occlusive material from a body vessel with acoustic phenomena resulting from radiation energy pulses delivered through optical fiber media to the vessel, and, more specifically, to methods and apparatus for generating flow within a body lumen to facilitate disruption of occlusive material and recanalization of the occluded vessel. The term "clot" is used herein to refer to a thrombus, embolus or some other total or partial occlusion of a vessel. The term "emulsify" means to break apart or disrupt by photo-acoustic or mechanical or other phenomena into particle(s) smaller than the original occlusive material.
Various embodiments for delivering radiation energy to body lumens for ablative and photo-acoustic recanalization have been previously disclosed. However, none of these embodiments is capable of generating fluid flow within the vessel that can be used to improve the degree of emulsification of an occlusion.
Therefore, it is an object of the present invention to provide techniques and apparatus that use pulsed radiation energy to generate fluid flow and/or to perform mechanical work within body lumens.
It is another object of the present invention to recanalize body vessels by disrupting total or partial occlusions using the disclosed flow techniques and apparatus.
It is a further object of the present invention to provide improved techniques for removing obstructions from the human body, particularly clots from cerebral blood vessels, without causing collateral damage to the vessel.
It is an object of the present invention to provide a method (and apparatus) for attracting rather than repelling occlusive material to the photo-acoustic source of disruption so as to potentially enhance the amount and/or degree of emulsification.
It is another object of the present invention to improve flexibility of the distal tip to improve the ability of the invention to access remote, tortuous vessel pathways.
Some or all of these objects are achievable with the various embodiments disclosed herein.